Molecular Distinctions between Stasis and Telomere Attrition Senescence Barriers Shown by Long-term Culture of Normal Human Mammary Epithelial Cells

Garbe, James C.; Bhattacharya, Sanchita; Merchant, Batul; Bassett, Ekaterina; Swisshelm, Karen; Feiler, Heidi S.; Wyrobek, Andrew J.; Stampfer, Martha R.

doi:10.1158/0008-5472.can-09-0270

Cited by 147 publications

(253 citation statements)

References 51 publications

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“…Consistent with previous reports (20), P1 CD10 + cells expressed a range of ME, luminal, and progenitor lineage markers (αSMA, CK19, oxytocin receptor, progesterone receptor, CK8, and myosin light chain kinase), whereas vCD10 + lacked expression of many genes associated with mammary differentiation ( Fig. 4B and Table S3).…”

Section: Characterization Of Breast Epithelial Cell Properties In Humsupporting

confidence: 91%

“…Because transformation of CD10 + cells resulted in the formation of metaplastic breast cancers, we reasoned that breast epithelial cells within the CD10 + population might contain cells with metaplastic potential, i.e., reduced mammary specification, before neoplastic transformation. Ex vivo cultivation of HMECs selects for variant cells that exhibit significant differences in gene-expression profiles, lineage markers, and chromatin methylation states compared with primary HMECs (20,21). We reasoned that these cells might be enriched within the CD10 + lineage and may exhibit features of alternate cell types.…”

Section: Characterization Of Breast Epithelial Cell Properties In Hummentioning

confidence: 99%

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Defining the cellular precursors to human breast cancer

Keller

Arendt

Skibinski

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

191

216

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Human breast cancers are broadly classified based on their geneexpression profiles into luminal-and basal-type tumors. These two major tumor subtypes express markers corresponding to the major differentiation states of epithelial cells in the breast: luminal (EpCAM + ) and basal/myoepithelial (CD10 + ). However, there are also rare types of breast cancers, such as metaplastic carcinomas, where tumor cells exhibit features of alternate cell types that no longer resemble breast epithelium. Until now, it has been difficult to identify the cell type(s) in the human breast that gives rise to these various forms of breast cancer. Here we report that transformation of EpCAM + epithelial cells results in the formation of common forms of human breast cancer, including estrogen receptor-positive and estrogen receptor-negative tumors with luminal and basal-like characteristics, respectively, whereas transformation of CD10 + cells results in the development of rare metaplastic tumors reminiscent of the claudin-low subtype. We also demonstrate the existence of CD10 + breast cells with metaplastic traits that can give rise to skin and epidermal tissues. Furthermore, we show that the development of metaplastic breast cancer is attributable, in part, to the transformation of these metaplastic breast epithelial cells. These findings identify normal cellular precursors to human breast cancers and reveal the existence of a population of cells with epidermal progenitor activity within adult human breast tissues.cell of origin | epidermal progenitor cells | luminal progenitors

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Section: Characterization Of Breast Epithelial Cell Properties In Humsupporting

confidence: 91%

Section: Characterization Of Breast Epithelial Cell Properties In Hummentioning

confidence: 99%

Defining the cellular precursors to human breast cancer

Keller

Arendt

Skibinski

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

191

216

View full text Add to dashboard Cite

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“…In that process, they also acquired additional aberrant properties, including numerous DNA methylation changes (3,27). We thus extended this work by examining normal, prestasis HMEC transduced with an shRNA targeting p16; this population does not express the aberrant methylation seen with the postselection HMEC (3).…”

Section: Resultsmentioning

confidence: 99%

TGF-β signaling engages an ATM-CHK2-p53–independent RAS-induced senescence and prevents malignant transformation in human mammary epithelial cells

Cipriano¹,

Kan²,

Graham³

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

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Oncogene-induced senescence (OIS), the proliferative arrest engaged in response to persistent oncogene activation, serves as an important tumor-suppressive barrier. We show here that finite lifespan human mammary epithelial cells (HMEC) undergo a p16/ RB-and p53-independent OIS in response to oncogenic RAS that requires TGF-β signaling. Suppression of TGF-β signaling by expression of a dominant-negative TGF-β type II receptor, use of a TGF-β type I receptor inhibitor, or ectopic expression of MYC permitted continued proliferation upon RAS expression. Surprisingly, unlike fibroblasts, shRNA-mediated knockdown of ATM or CHK2 was unable to prevent RAS-mediated OIS, arguing that the DNA damage response is not required for OIS in HMEC. Abrogation of TGF-β signaling not only allowed HMEC lacking p53 to tolerate oncogenic RAS but also conferred the capacity for anchorage-independent growth. Thus, the OIS engaged after dysregulated RAS expression provides an early barrier to malignant progression and is mediated by TGF-β receptor activation in HMEC. Understanding the mechanisms that initiate and maintain OIS in epithelial cells may provide a foundation for future therapies aimed at reengaging this proliferative barrier as a cancer therapy. (ii) constitutive growth signaling, (iii) unlimited replication potential, and (iv) invasive potential (1). Early studies using normal mouse cells indicated that a limited set of genetic manipulations could confer neoplastic potential (2). However, normal human cells have been more difficult to transform to malignancy, indicative of their more stringent tumor-suppressive pathways. Extensive study of cultured human mammary epithelial cells (HMEC) has identified two senescence barriers. One involves the stress-associated induction of the cyclin-dependent kinase inhibitor p16 before attaining critically short telomeres. This stasis barrier can be overcome by inhibiting p16, allowing continued proliferation, which results in agonescence, a proliferative barrier mediated by telomere depletion (3). Additionally, the ability of dysregulated oncogenic signaling to induce senescence in human cells has implicated oncogene-induced senescence (OIS) as an important tumor-suppressive barrier. A number of recent studies have demonstrated the physiological relevance of OIS in human tumorigenesis and in vivo tumor mouse models (4). Additionally, the presence of senescent cells in benign but not advanced tumors argues that OIS serves as an early tumorsuppressive barrier that needs to be dismantled for full oncogenic progression (4). In human fibroblasts, OIS could be bypassed by disabling p16 or molecular components of the DNA damage response (DDR), including ATM, CHK2, or p53, before RAS, MOS, or STAT5 overexpression (5-9). However, OIS in HMEC has been shown to be independent of p53 and the p16-RB pathway after oncogenic RAF-1 expression (10). The contrasting responses between epithelial and fibroblast cells argue that the signaling networks responsible for OIS have tissue specificity. Indeed, fibrob...

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“…19,41,116 Non-immortalized 48RS-HMEC between passages 8 and 16 were grown in Medium 171 (Invitrogen, cat.# M171500, https://www.thermofisher.com/order/catalog/product/ M171500) supplemented with mammary epithelial growth supplement (MEGS; Invitrogen, cat.# S0155, https://www.thermo fisher.com/order/catalog/product/S0155) in a humidified atmosphere containing 5% CO 2 at 37 C as described previously. 42,71 Phoenix-Ampho (ATCC, cat.…”

Section: Cell Culture Conditions and Reagentsmentioning

confidence: 99%

STAT3-mediated SMAD3 activation underlies Oncostatin M-induced Senescence

et al. 2017

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Cytokines in the developing tumor microenvironment (TME) can drive transformation and subsequent progression toward metastasis. Elevated levels of the Interleukin-6 (IL-6) family cytokine Oncostatin M (OSM) in the breast TME correlate with aggressive, metastatic cancers, increased tumor recurrence, and poor patient prognosis. Paradoxically, OSM engages a tumor-suppressive, Signal Transducer and Activator of Transcription 3 (STAT3)-dependent senescence response in normal and non-transformed human mammary epithelial cells (HMEC). Here, we identify a novel link between OSM-activated STAT3 signaling and the Transforming Growth Factor-b (TGF-b) signaling pathway that engages senescence in HMEC. Inhibition of functional TGF-b/SMAD signaling by expressing a dominant-negative TGF-b receptor, treating with a TGF-b receptor inhibitor, or suppressing SMAD3 expression using a SMAD3-shRNA prevented OSMinduced senescence. OSM promoted a protein complex involving activated-STAT3 and SMAD3, induced the nuclear localization of SMAD3, and enhanced SMAD3-mediated transcription responsible for senescence. In contrast, expression of MYC (c-MYC) from a constitutive promoter abrogated senescence and strikingly, cooperated with OSM to promote a transformed phenotype, epithelial-mesenchymal transition (EMT), and invasiveness. Our findings suggest that a novel STAT3/SMAD3-signaling axis is required for OSM-mediated senescence that is coopted during the transformation process to confer aggressive cancer cell properties. Understanding how developing cancer cells bypass OSM/STAT3/SMAD3-mediated senescence may help identify novel targets for future "pro-senescence" therapies aiming to reengage this hidden tumor-suppressive response.

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Molecular Distinctions between Stasis and Telomere Attrition Senescence Barriers Shown by Long-term Culture of Normal Human Mammary Epithelial Cells

Cited by 147 publications

References 51 publications

Defining the cellular precursors to human breast cancer

Defining the cellular precursors to human breast cancer

TGF-β signaling engages an ATM-CHK2-p53–independent RAS-induced senescence and prevents malignant transformation in human mammary epithelial cells

STAT3-mediated SMAD3 activation underlies Oncostatin M-induced Senescence

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